Froth flotation is a process for recovering and concentrating minerals from ores. In a froth flotation process, the ore is crushed and wet ground to obtain a pulp. Additives such as mineral flotation or collecting agents, frothing agents, depressants, stabilizers, etc., are added to the pulp to assist separating valuable minerals from the undesired or gangue portions of the ore in subsequent flotation steps. The pulp is then aerated to produce a froth at the surface. The minerals which adhere to the bubbles or froth are skimmed or otherwise removed and separated. The froth product or the reject product or both can then be further processed to obtain the desired minerals. Typical mineral flotation collectors include xanthates, amines, alkyl sulfates, arenes, sulfonates, dithiocarbamates, dithiophosphates, fuel oils, and thiols.
It is a continuing goal in the ore-processing industry to increase the productivity of ore flotation processes and, above all, to provide specific procedures which are selective to one ore or metal over other ores or metals present in the treated material. For example, since iron and lead are among the most readily floated metals, it is frequently difficult to obtain selective recovery of one in the presence of significant quantities of the other.